This disclosure describes, generally, tools to allow more intuitive display and/or definition of ranges in software applications. Merely by way of example, a software application might include a user interface that has a graphical element (such as a line, a bar, and/or the like) that represents a spectrum of values. The application might further include one or more markers that serve to define boundaries of one or more ranges within the spectrum. By allowing a user to move the markers (through manipulation of the markers using a mouse, typing values for the markers, and/or the like), the interface can allow the user to quickly and easily define different ranges of values and/or to view defined ranges. In an aspect, a marker (and/or an accompanying indicator) may be configured to indicate to the user whether the value represented by the marker falls within or outside the range bounded by the marker.